Thermodynamic reassessment of the Cr−O system in the framework of solid oxide fuel cell (SOFC) research

Povoden, Erwin; Grundy, A. Nicholas; Gauckler, Ludwig J.

doi:10.1007/s11669-006-0007-1

Cited by 10 publications

(12 citation statements)

References 37 publications

(72 reference statements)

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“…Figure 2 indicates that in the low aluminum region, where there is little deviation between Henryan activity and composition, the values calculated by TCFE7 and SLAG3 are quite close and agree well with the results of Janke and Fischer [27] as well as Kang and co-workers [7]. The values of Janke and Fischer, based on EMF measurements, need some correction due to the presently accepted values for the Cr-Cr2O3 equilibrium [36]. Apparently, the values calculated by SLAG3, are a reasonable prediction up to around 0.24%Al.…”

Section: Experimental Datasupporting

confidence: 83%

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Silva¹,

Avillez²,

Neto³

2018

ABM Proceedings

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ResumoO sistema ferro-oxigênio alumino tem sido investigado há muitos anos em função de sua importância para a indústria do aço. Uma grande fração de todo o aço plano produzido é de aço de baixo carbono acalmado ao alumínio, não apenas pelo baixo conteúdo de oxigênio residual em solução que pode ser obtido mas, também, pela importância do alumínio residual na formação de AlN, ferramenta importante no controle de estrutura e textura obtidas. O sistema Fe-O é relativamente bem compreendido e quantificado, da mesma forma que o sistema Fe-Al. Entretanto, há discrepâncias significativas na quantificação do comportamento do sistema Fe-Al-O havendo, ainda, bastante controvérsia com respeito a equilíbrios importantes. Assim, o objetivo deste trabalho é (a) realizar uma revisão crítica dos experimentos e avaliações termodinâmicas principalmente do equilíbrio Al-Fe-O-Al2O3 (b) avaliar os métodos atualmente usados para descrever este equilíbrio e (c) apresentar recomendações sobre os dados, com base em sua confiabilidade e consistência. Palavras-chave: Aço; Desoxidação; Sistema Fe-Al-O; Termodinâmica, CALPHAD LIQUID IRON DEOXIDATION BY ALUMINUM: A BRIEF REVIEW OF EXPERIMENTAL DATA AND THERMODYNAMIC DESCRIPTION AbstractThe iron-oxygen-aluminum equilibrium has been a subject of interest for many years for its importance in the steel industry. A great percentage of all flat rolled steel is aluminum killed "AK" (deoxidized) low-carbon steel, not only because of the low soluble oxygen contents that can be achieved but also because of the importance of the residual aluminum in forming aluminum nitride that is one of the main tools used to achieve crystallographic texture adequate for forming. The behavior of oxygen in liquid iron is relatively well understood and quantified, as is the behavior of aluminum in iron. Nonetheless, the Fe-Al-O system is not fully understood and considerable controversy still prevails. Thus, the objectives of this work is (a) to critically review the experimental work and assessments performed mainly of the Al-Fe-O-Al2O3 equilibrium, (b) to evaluate the current models used to describe this equilibrium and (c) to present a recommendation of the data, based on its reliability and consistency.

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Section: Experimental Datasupporting

confidence: 83%

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Silva¹,

Avillez²,

Neto³

2018

ABM Proceedings

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“…A partial explanation for the overestimation in the calculation could be the oxygen deficiency of the eskolaite, which is not modelled by Degterov and Pelton 13 . This phenomenon was recently modelled by Povoden et al 28 for pure Cr 2 O 3− x . Extension of this model to (Cr,Al) 2 O 3 could provide a stabilization of eskolaite under reducing atmospheres and, hence, a lower solubility.…”

Section: Discussionmentioning

confidence: 83%

Determination of CaO–SiO₂–MgO–Al₂O₃–CrO_x Liquidus

Arnout

Durinck

Guo

et al. 2008

Journal of the American Ceramic Society

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In this work, the liquidus of synthetic CaO–SiO2–MgO–Al2O3–CrOx slags is evaluated in the industrially relevant compositional domain. Equilibrium experiments are carried out at 1500°C and partial oxygen pressure (pO2) 10−11.04 atm, and at 1600°C and pO2=10−10.16 and 10−9.36 atm. The studied basicities (CaO/SiO2) are 1.2 and 0.5. Al2O3 levels range from 0 to 30 wt%. Oversaturated liquid is sampled and phase relations are measured with quantitative electron probe microanalysis–wavelength dispersive spectroscopy (EPMA–WDS). The results are compared with the commercially available FactSage thermodynamic databases. Qualitative agreement is always obtained. Also a good quantitative agreement is found at the higher basicity, especially for the spinel liquidus. A minor but systematic deviation can be observed for the eskolaite liquidus. At the lower basicity, the calculated phase diagram deviates strongly from the experimental results, probably due to missing ternary interactions in the database.

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“…Using a two-sublattice ionic model for the liquid, the CaO-SiO 2 system was optimized by Hillert et al, 19 and MgO-SiO 2 was optimized by Hillert and Wang. 20 Povoden et al 21 studied the system Cr-Cr 2 O 3 . The CaO-MgO system was modeled by Hillert et al 22 Finally, the ternary system CaO-SiO 2 -MgO was assessed by Huang et al 23 With the associate liquid model, Besmann and Spear 24 optimized the CaO-SiO 2 system and Besmann et al 25 investigated Cr 2 O 3 -SiO 2 , but without pO 2 dependence.…”

mentioning

confidence: 99%

Experimental Determination of CaO–CrO–Cr₂O₃–MgO–SiO₂ and Thermodynamic Modeling of the CrO–Cr₂O₃–MgO–SiO₂ System

Arnout

Guo

Jung

et al. 2009

Journal of the American Ceramic Society

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This article focuses on the CaO–CrOx–MgO–SiO2 system at low CaO contents, providing quantitative phase relation data, and improving the thermodynamic description. The observed liquidus data are compared with literature data and state‐of‐the‐art thermodynamic calculations (FactSage 5.5). The experimental phase diagram measurements are performed under various conditions: (1) liquidus of CaO–CrOx–MgO–SiO2 at a basicity CaO/SiO2=0.5 (by weight), at 1500°C and at a partial oxygen pressure pO2=10−11.04 atm, (2) liquidus of CaO–CrOx–MgO–SiO2 at 1600°C and pO2=10−9.36 atm with constant molar ratio Mg/Cr of 1/2 and varying basicity, (3) phase equilibria of the CrO–Cr2O3–MgO–SiO2 system at 1600°C and pO2 ranging from air to equilibrium with metallic chromium. In the experiments, equilibrium samples of crystalline phases and melts are analyzed by electron probe microanalysis using wavelength dispersive spectroscopy to determine both solid and liquid compositions. Some discrepancies from previous literature data and calculations are found. In order to improve the thermodynamic calculations, a new thermodynamic model of the CrO–Cr2O3–MgO–SiO2 system is also developed using the Modified Quasichemical Model for the liquid and the compound energy formalism for the solid solution phases. The newly optimized model parameters can describe the present experimental data and literature data more accurately.

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Thermodynamic reassessment of the Cr−O system in the framework of solid oxide fuel cell (SOFC) research

Cited by 10 publications

References 37 publications

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Determination of CaO–SiO₂–MgO–Al₂O₃–CrO_x Liquidus

Experimental Determination of CaO–CrO–Cr₂O₃–MgO–SiO₂ and Thermodynamic Modeling of the CrO–Cr₂O₃–MgO–SiO₂ System

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Thermodynamic reassessment of the Cr−O system in the framework of solid oxide fuel cell (SOFC) research

Cited by 10 publications

References 37 publications

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Desoxidação Do Ferro Por Alumínio: Uma Breve Revisão Dos Dados Experimentais E Descrições Termodinâmicas

Determination of CaO–SiO2–MgO–Al2O3–CrOx Liquidus

Experimental Determination of CaO–CrO–Cr2O3–MgO–SiO2 and Thermodynamic Modeling of the CrO–Cr2O3–MgO–SiO2 System

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Determination of CaO–SiO₂–MgO–Al₂O₃–CrO_x Liquidus

Experimental Determination of CaO–CrO–Cr₂O₃–MgO–SiO₂ and Thermodynamic Modeling of the CrO–Cr₂O₃–MgO–SiO₂ System